Github Copilot Plugin failed to find agent.js

Go to Menu->Edit->Preferences... In the pop-up Preferences - Qt Creator Dialog, filter to Copilot and go to Copilot page, it writes "Otherwise you need to specify the path to the agent.js file from the Copilot neovim plugin." However, the link to agent.js is 404 - page not found.

I've installed neovim v0.9.1 (Build type: RelWithDebInfo) (LuaJIT 2.1.0-beta3) following README.md of https://github.com/github/copilot.vim, Using GitHub Copilot, and Getting started with GitHub Copilot - GitHub Docs and Node.js 20.8.0, but Qt Creator cannot find the agent.js file automatically as it says. Besides, the "Sign In" button is unavailable, even though I have an active GitHub Copilot subscription.